Cassettes for receiving glass substrates

ABSTRACT

Cassettes for receiving objects. The cassettes include a frame, a sidewall and a cantilever. The sidewall is perpendicular to a horizon. The cantilever for supporting the object includes a fixed-end attached to the sidewall, thereby forming an angle with the horizon.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to cassettes, and more particularly, tocassettes for receiving glass substrates of liquid crystal displays(LCDs).

2. Discussion of the Related Art

Panels of display devices often comprise transparent substrates, whichare becoming increasingly thinner and reducing the size, weight ofproducts. Transparent substrates comprise glass, quartz, or organictransparent materials such as polycarbonate (PC), poly methylmethacrylate (PMMA). In a thin film transistor-liquid crystal displays(TFT-LCDs) manufacturing process, glass substrates of the panel or otherplate-like objects are loaded and stored in a cassette, and can be movedor transported by mechanical arms.

As shown in FIG. 1A, glass substrates S₁′ are stored in a cassette C.The cassette C comprises a frame 100′ and a plurality of cantilevers101′ and 102′. The frame 100′ is rectangular. The cantilevers 101′ and102′ are evenly disposed on inner walls 110′ and 120′ of the frame 100′.The frame 100′ is divided into a plurality of floors 105. Each floor 105has a height H_(p), which is a floor pitch or distance between floors.Each substrate S₁′ is supported by two cantilevers 101′ and 102′ at thesame level.

FIG. 1B is a front view of the conventional cassette C when a mechanicalarm M is transferring a glass substrate S₁′ therein. The mechanical armM comprises a first support portion 5′ and a second support portion 6′with a predetermined distance W′ therebetween. When the mechanical arm Mtransports the substrate S₁′, the mechanical arm M moving into anassigned floor 105 of the cassette C, transfers the substrate S₁′ on thecantilever 101′ and 102′, thereby completing storage of the substrateS₁′. Conversely, when taking the substrate S₁′ out of the cassette C,the mechanical arm M moves into the cassette C directly under thesubstrate S₁′, and the support portions 5′ and 6′ thereof simultaneouslysupport the substrate S₁′ and move it out of the cassette C.

The substrate S₁′ is supported by the cantilevers 101′ and 102′ on theinner walls 110′ and 120′ of the cassette C; however, due to theself-weight of the substrate S₁′, a central portion thereof is slightlydeformed downward.

Furthermore, the glass substrates are categorized into variousgenerations with different dimensions such as the 2.5-generation (370 mmby 470 mm), the 3^(rd)-generation (550 mm by 650 mm), the 3.5-generation(660 mm by 720 mm), the 4^(th)-generation (680 mm by 880 mm), the5^(th)-generation (1100 mm by 1250 m). The trend is toward even largersubstrate sizes, such as 6^(th)- or 7^(th)-generation substrates (about1900 mm by 2200 mm). The thickness thereof is reduced from 0.7 mm to thecurrent 0.4 mm. That is, the substrates are larger and thinner, andthus, the deflection ratio of the central portion of the substrates isincreased.

When the mechanical arm M is loading the large and thin substrate S₁′,each end E₁ of the substrate S₁′ is naturally deflected downward byself-weight, as shown in FIG. 1C. H_(c) is the deflected length of theend E₁. In the conventional cassette C, during transportation, if themisalignment of the mechanical arm M is severe enough, it may cause oneend E₁ of the substrate S₁′ to strike the cantilevers 101′ and 102′ ofthe cassette C and break inside the cassette C. Thus, yield rate isreduced, wasting materials and increasing process time.

To safely transport the substrates S₁′ from the cassette C, the distanceH_(p) must be greater than H_(c). The distance H_(p) of each floor 105must be increased to avoid contact between the ends E₁, E₂ of thesubstrate S₁′ and the cassette C. Thus, the large substrates require alarger sized cassette. Furthermore, due to space constraints, thecassette must be appropriately sized for convenience during storage andremoval of the substrates, and thus, the storage volume of the cassetteC is reduced accordingly. Hence, reduction of defects in the glasssubstrate when transferred from one position to another is critical.

SUMMARY OF THE INVENTION

Accordingly, an object of the present invention is improving cassetteand to safely transport the objects not struck the cassette duringtransportation.

Another object of the present invention to change the cantilevers shapedof the cassette, which to reduce the total height and weight of thecassette.

Further another object of present invention to increased the flooramount, which to increase the stored amount of objects.

For the purpose of the present invention, cassettes are provided. Anexemplary embodiment of a cassette for receiving an object comprises asidewall and a cantilever. The sidewall is perpendicular to a horizon.The cantilever for supporting the object comprises a fixed-end attachedto the sidewall, thereby forming an angle with the horizon, and theangle in the range of about 1° to 10°.

The cantilever further comprises a front-end, and a lower portion of thefront-end comprises a notch. The thickness of the cantilever decreasesalong the front-end.

Additionally, the lower portion of the front-end is substantiallystep-shaped. The cassette further comprises a pad, and the pad isdisposed on the front-end. The pad comprises an elastic polymer such asrubber, soft Polypropylene, or like.

Further provided is a cassette for receiving an object comprising asidewall and a cantilever. The sidewall is perpendicular to a horizon.The cantilever for supporting the object comprises a fixed-end attachedto the sidewall and a front-end having a thickness less than that of thefixed-end. The front-end comprises a notch. The thickness of thecantilever decreases from the fixed-end to the front-end. Moreover, thefront-end is substantially step-shaped. The cassette further comprises apad, disposed on the front-end. The pad comprises an elastic polymersuch as rubber, soft Polypropylene, or like.

Some embodiments of a cassette for receiving an object comprise a firstsidewall, a first cantilever, a second sidewall, and a secondcantilever. The first sidewall is perpendicular to a horizon. The firstcantilever is disposed on the first sidewall. The second sidewallopposes and parallel to the first sidewall. The second cantilever isdisposed on the second sidewall. The first cantilever and the horizonform a first angle, and the second cantilever and the horizon form asecond angle. The first angle and the second angle are substantiallyidentical.

DESCRIPTION OF THE DRAWINGS

Cassettes for receiving glass substrates can be more fully understood byreading the subsequent detailed description in conjunction with theexamples and references made to the accompanying drawings, wherein:

FIG. 1A is a schematic internal view of a conventional cassette;

FIG. 1B is a front view of the conventional cassette with a mechanicalarm;

FIG. 1C is a local enlarged view of the conventional cassette;

FIG. 2A is a front view of an embodiment of a cassette;

FIG. 2B is a front view of the cassette with a mechanical arm of theFIG. 2A;

FIG. 2C is a local enlarged view of a first cantilever of the cassetteof the FIG. 2A;

FIG. 3A is a front view of an embodiment of a cassette;

FIG. 3B is a front view of an embodiment of the cassette with amechanical arm of the FIG. 3A;

FIG. 3C is a local enlarged view of a first cantilever of the cassetteof the FIG. 3A;

FIG. 3D is a local enlarged view of a variation of the first cantileverof the cassette of the FIG. 3A;

FIG. 4A is a front view of an embodiment of a cassette;

FIG. 4B is a front view of an embodiment of the cassette of the FIG. 4Awith a mechanical arm;

FIG. 4C is a local enlarged view of a first cantilever of the cassetteof the FIG. 4A;

FIG. 4D is a local enlarged view of a variation of the first cantileverof the cassette of the FIG. 4A.

DETAILED DESCRIPTION

Cassettes for receiving glass substrates are provided. An exemplaryembodiment of a cassette for receiving glass substrates is applicable toa TFT-LCD panel manufacturing process when transporting a plurality ofobjects such as glass substrates or other plate-shaped objects in acassette by a mechanical arm M. The cassette is used to load and storethe objects S₁. The mechanical arm M can enter the cassette and movehorizontally upward or downward to transfer the object S₁.

FIG. 2A is a front view of an embodiment of a cassette C₁. The cassetteC₁ comprises a frame 100, a first sidewall 110, a second sidewall 120, afirst cantilever 11, and a second cantilever 12. Note that the quantityof cantilevers is not limited to two, and the cassette C₁ can comprise aplurality of cantilevers. In some embodiments, the first cantilever 11and the second cantilever 12 are provided.

The first sidewall 110 and the second sidewall 120 are perpendicular toa horizon h. The second sidewall 120 is opposing and parallel to thefirst sidewall 110. The first cantilever 11 comprises a first fixed-end11 a and a first front-end 11 b. The first fixed-end 11 a is attached tothe first sidewall 110. The second cantilever 12 comprises a secondfixed-end 12 a and a second front-end 12 b. The second fixed-end 12 a isattached to the second sidewall 120. The object S₁ is supported by thefront-ends 11 b and 12 b of the cassette having a plurality of pads 160disposed thereon, preventing direct contact between the object S₁ andthe cantilevers 11 and 12.

The first cantilever 11 and the horizon h form a first angle θ₁. Thesecond cantilever 12 and the horizon h form a second angle θ₂. The firstangle θ₁ is substantially identical the second angle θ₂. The first andsecond angles θ₁, θ₂ in the range of about 1° to 10°, preferably rangeof about 1° to 4°, varying with the length, thickness, weight andmaterials of the object S₁.

FIG. 2B is a front view of the cassette C₁ with a mechanical arm M. FIG.2C is a local enlarged view of a first cantilever 11 of the cassette C₁.The mechanical arm M comprises two support portions 5 and 6 locatedinside a floor 150 of the cassette C, supporting one of the objects S₁.When supported by the mechanical arm M, two ends of the object S₁ isdeformed downward. The first angle θ₁ of the first cantilever 11 issubstantially identical an inclined angle θ₁′ of the end section E ofthe object S₁. Thus, the first cantilever 11 is substantially parallelto the section E.

Since the shapes of the cantilevers and the end sections of the objectsare similar and parallel, the end section E does not strike thecantilevers when the mechanical arm M loading the substrate moves up ordown therebetween, preventing breakage of the substrate.

Furthermore, as shown in FIG. 2C, the first cantilever 11 is inclinedupward, an additional height D₁ is provided for the floor 105 near thefront-end 11 b, and thus, distance between floors of the cassette can beincreased. The additional height D₁ provides sufficient clearance,preventing contact between the object S₁ and the cantilevers 11 and 12during transportation. Since the distance between the floors 105 in thecassette C₁ can be reduced, the overall size of the cassette C₁ can bereduced, providing a more compact sized cassette. Under othercircumstances, when a larger storage capacity is required, since thedistance between the floors can be reduced, the overall size of thecassette C₁ can remain the same but more floors can be added for storingmore objects. Hence, the capacity of the cassette C₁ can be increasedwithout increasing overall size thereof.

FIGS. 3A, 3B, and 3C are schematic views of an embodiment of thecassette C₂. The cassette C₂ comprises a frame 200, a first sidewall210, a second sidewall 220, a first cantilever 21, and a secondcantilever 22. Note that explanations of elements and connectingstructures common to the previously described embodiments are omitted.

As shown in FIG. 3A-3C, the difference is that the shapes of thefront-ends 21 b and 22 b of the first cantilever 21 and the secondcantilever 22 are different. The thickness of the front-ends 21 b and 22b is less than that of the fixed-ends 21 a and 22 a. That is, the firstfront-end 21 b of the first cantilever 21 comprises a notch 25, and thesecond front-end 22 b of the second cantilever 22 comprises a notch 26.The cantilevers 21 and 22 are substantially step-shaped.

Moreover, the first and the second cantilevers 21 and 22 remainhorizontal, unlike the inclined cantilevers in some embodiments.Similarly, the pads 260 are disposed on the first and second cantilevers21, 22 to prevent direct contact of the object S₂.

FIG. 3B is a front view of the cassette C₂ with a mechanical arm M. FIG.3C is a local enlarged view of a first cantilever of the cassette C₂. Asshown in FIGS. 3B and 3C, the mechanical arm M is located on a floor 250of the cassette C₂ and loads one of the objects S₂ by the supportportions 5 and 6 thereof. When the mechanical arm M is loading theobject S₁, two end sections E thereof are slightly deflected downward.Since the first front-end 21 b of the first cantilever 21 comprises anotch having a height D₂, which varies with inclined angle of the endsections E of the object S₂, the notch 25 provides an additionaltransport space for the mechanical arm M such that contact between theend section E and the first cantilever can be prevented. Thus, the floorpitch H₂ of the cassette C₂ can be reduced accordingly. The overall sizeof the cassette C₂ can be reduced, providing a more compact sizedcassette. In some embodiments, when larger storage capacity of thecassette C₂ is required, since distance between the floors can bereduced, the overall size of the cassette C₂ can remain the same andmore of the floors can be added for storing more objects. Hence, thecapacity of the cassette C₂ can be increased without increasing overallsize thereof.

The cassette further has a variation. As shown in FIG. 3D, from whichcommon elements share the same symbols and description thereof isomitted. The first cantilever 21′ is provided as an example. The firstcantilever 21′ and the horizon h form a third angle θ₃, and the thirdangle in the range of about 1° to 10°, and the third angle θ₃ preferablyrange of about 1° to 4°.

Since the first cantilever 21′ and the second cantilever 21′ aresymmetrically arranged, the figure of the second cantilever 22′ isomitted. Although not shown, the second cantilever 22′ has substantiallyidentical angle θ₃ as that of the first cantilever 21′. The third angleθ₃ varies with the length, thickness, weight and materials of the objectS₂.

Since the cantilever is inclined at the third angle θ₃, an additionalheight D₃ is provided to increase transport space in the cassette. Thus,each floor pitch H₂′ can be reduced accordingly. In this variation, thefloor pitch H₂′ is less than the floor pitch H₂. Since floor pitch H₂ orH₂′ can be reduced, capacity of the cassette C₂ can be increased.

FIGS. 4A, 4B, and 4C are schematic views of the cassette C₃. Thecassette C₃ comprises a frame 300, a first sidewall 310, a secondsidewall 320, a first cantilever 31, and a second cantilever 32.

The difference is the shape of the front-ends 31 b and 32 b of the firstand second cantilevers 31 and 32. The thickness of the front-ends 31 band 32 b of the first and second cantilevers 31 and 32 is less than thatof the fixed-ends 31 a and 32 a. The thickness of the cantilevers 31 and32 decreases from the fixed-ends 31 a and 32 a along the front-ends 31 band 32 b.

As shown in FIGS. 4B and 4C, a section P₁ of the first cantilever 31comprises a slope 33, forming a fourth angle θ₄ with the horizon h. Theslope 33 of the section P₁ of the first cantilever 31 is substantiallyparallel to the end section E of the object S₃ with similar shapes.Likewise, the second cantilever 32 has a slope forming a fifth angle θ₅with the horizon h. The additional distance D₄ provides extra transportspace. Thus, contact between the end section E of the objects S₃ and thecantilevers 31 and 32 can be prevented when the mechanical arm M loadsthe object.

Note that, in some embodiments, the first and second cantilevers 31 and32 remain horizontal. That is, the first and second cantilevers 31 and32 are perpendicular to the first and second sidewalls 310 and 320.Moreover, elastic pads 360 can be disposed on the first and secondcantilevers 31, 32, preventing direct contact between the object S₃ andthe cantilevers 31, 32.

Thus, since the floor pitch H₃ of the cassette C₃ can be reducedaccordingly, the overall size of the cassette C₃ can be reduced,potentially providing a more compact sized cassette. In someembodiments, when larger storage capacity of the cassette C₃ isrequired, since distance between the floors can be reduced, the overallsize of the cassette C₃ can remain the same, and more of the floors canbe added for storing more objects. Hence, the capacity of the cassetteC₃ can be increased without increasing overall size thereof.

The cassette C₃ has a variation. As shown in FIG. 4D, from which commonelements share the same symbols and description thereof is omitted. Thefirst cantilever 31′ is provided as an example. The first cantilever 31′and the horizon h form a sixth angle θ₆, the sixth angle in the range ofabout 1° to 10°, and the sixth angle θ₆ preferably range of about 1° to4°. Since the first cantilever 31′ and the second cantilever 31′ aresymmetrically arranged, the figure of the second cantilever 32′ isomitted. Although not shown, the second cantilever 32′ has the samesixth angle θ₆ as that of the first cantilever 31′. The sixth angle θ₆varies with the length, thickness, weight and materials of the objectS₃.

Since the cantilever 31′ is inclined at the sixth angle θ₆, anadditional height D₄ is provided to increase transport space in thecassette. Thus, each floor pitch H₃′ can be reduced accordingly. In thisvariation, the floor pitch H₃′ is less than the floor pitch H₃ of thecassette C₃. Since floor pitch H₃ or H₃′ can be reduced, capacity of thecassette C₃ can be increased.

Cassettes for receiving glass substrates may prevent contact between theobjects and the cantilevers during transport and provide a compactcassette with lighter weight and reduced height.

While the invention has been described by way of example and in terms ofpreferred embodiment, it is to be understood that the invention is notlimited thereto. To the contrary, it is intended to cover variousmodifications and similar arrangements (as would be apparent to thoseskilled in the art). Therefore, the scope of the appended claims shouldbe accorded the broadest interpretation so as to encompass all suchmodifications and similar arrangements.

1. A cassette, comprising: a frame having two sidewalls perpendicular toa horizon; and a plurality of cantilevers, each having a front-end and afixed-end attached to one of the two sidewalls, thereby forming an anglewith the horizon.
 2. The cassette of claim 1, wherein the angle is inthe range of about 10 to
 100. 3. The cassette of claim 1, wherein thefront-end comprises a notch.
 4. The cassette of claim 1, wherein thethickness of each of the cantilevers decreases along the front-end. 5.The cassette of claim 1, wherein a lower portion of the front-end issubstantially step-shaped.
 6. The cassette of claim 1, furthercomprising a pad disposed on the front-end.
 7. The cassette of claim 6,wherein the pad comprises an elastic polymer.
 8. A cassette, comprising:a frame having two sidewalls perpendicular to a horizon; and a pluralityof cantilevers, each having a front-end and a fixed-end attached to oneof the two sidewalls, the front-end having a thickness less than that ofthe fixed-end.
 9. The cassette of claim 8, wherein the front-endcomprises a notch.
 10. The cassette of claim 8, wherein the thickness ofeach of the cantilevers substantially gradually decreases from thefixed-end to the front-end.
 11. The cassette of claim 8, wherein thefront-end is substantially step-shaped.
 12. The cassette of claim 8,further comprising a pad disposed on the front-end.
 13. The cassette ofclaim 12, wherein the pad comprises an elastic polymer.